6500 lumens enough?

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Cynx

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Joined 2005
#1
Hi everybody,

i have to choose between a 36V/400W 6500 Lumens OHP (Medium 5000) and one with a 650W lamp (Polylux 1).

Should i better buy the one with the 650W lamp? Or is 6500 lumens enough?

Thanks in advance!

Cynx
 
#2
Nope and nope. The 400W bulbs typically used for a DIY projector are 36,000 to 40,000 lumens. The 250W are typically around 20,000 to 25,000 lumens. So at 6500 lumens, you're talking about 1/6th the output. That'd be IMHO too dark. What you can do, and many people have done, is replace the bulb and power supply with a 400W metal halide bulb and balast. That will put you about on par for brightness.
 
#4
Cynx said:
Hi everybody,

i have to choose between a 36V/400W 6500 Lumens OHP (Medium 5000) and one with a 650W lamp (Polylux 1).

Should i better buy the one with the 650W lamp? Or is 6500 lumens enough?

Thanks in advance!

Cynx
Click to expand...


6500 lumens would be enought to watch with no ambient light ( totally dark ). The more important choose would be... which one has the better optics? One million lumens would be worthless if you cant get the corners of your LCD focused. lol Pick the one with the better optics and if it's not bright enough down the road then you can retrofit it with a metal halide bulb.

Zaner21
 
#5
superdaveumo said:
Nope and nope. The 400W bulbs typically used for a DIY projector are 36,000 to 40,000 lumens. The 250W are typically around 20,000 to 25,000 lumens. So at 6500 lumens, you're talking about 1/6th the output. That'd be IMHO too dark. What you can do, and many people have done, is replace the bulb and power supply with a 400W metal halide bulb and balast. That will put you about on par for brightness.
Click to expand...


Superdaveumo, I think you’re talking about apples and oranges or really, more like, Granny Smith apples vs Golden Delicious apples. You are correct about the lumens but the 6500, I believe, would be what is measure at the screen where your 40k - 20k are mean lumens that are being scattered in every direction from the bulb. The 40k lumens that are being produce don't all make it to the projector screen. If I am wrong I apologize but I don’t believe that the 6500 is mean lumens from the overhead projectors halogen bulb. 🙂

Zaner21
 
#6
Here is a few pictures of my 5000 lumen OHP with 400w bulb, triplet OHP lens in ambient light and in darker conditions. Would 6500 lumens be enough? That would depend on when and what conditions you want to watch your movies in.

Ambient light

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Later on in the day

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#8
The lumen rating for an OHP is totally different. The OHP's lumen rating refers to the luminosity you will achieve on a white screen if you use the OHP (when it was new) with a transparency; not an LCD. Now that I think of it, 6500 lumens is almost definitely not the rating of the bulb and it is certainly not the rating on your screen going through an LCD.

When I replied to your thread, I assumed you looked at the bulb and saw it was rated for 6500 lumens. That definitely won't cut it. I take it that is not what you were reading from. I think you were referring to the OHP manufacture's lumen rating (which is again, for a transparency on a white screen).

So, a better question to ask us is, is my bulb bright enough? To ask us this though, you'll have to find the lumen rating for the bulb; not the overall OHP. Just pull the bulb out and do a google on whatever info you can attain from it. Lumen rating should be on there someplace.

As for retrofitting, yes, tons of people have done it. There might be PLOGs, but I wouldn't think there was a tutorial for OHP because they will differ depending on the OHP that you are using and the bulb/mount that you retrofit. But the basic idea is, rip the power supply, bulb, and mount out of the OHP. Drill holes in the metal casing so that the new parts can be mounted in there. Make sure the bulb's arc is exactly (or close to it) where the original bulb's arc used to be. This will ensure your optics work properly with the new setup. You might have to rewire the fan(s) too. Not that hard.

Keep going with this. I'm sure that you can find a solution to this.
 
#9
Cynx said:
@zaner21

How can i retrofit an OHP with a metal halide bulb? Are there any tutorials on how to do it?

And what do you mean by "better optics". here are the links to both ohp`s, can you see which one has the better optics?

http://cgi.ebay.de/ws/eBayISAPI.dll...40020920210&rd=1&sspagename=STRK:MEWA:IT&rd=1

http://cgi.ebay.de/ws/eBayISAPI.dll...60023746800&rd=1&sspagename=STRK:MEWA:IT&rd=1
Click to expand...


You would want at least a dublet but a triplet would be better. I tried searching for both of those to see if I could find in spec but didn't come up with anything. IMO I would pick the Medium 5000 (6500 Lumens one). I don't think you will get that many more, if any, lumens to justify the 50%+ increase in power and probably heat. If you can email the sellers and see if they will look at each bulb and give you the ansi code for them. You could then search, like Superdave, said and see what kind of lumens they each put out. Just a guess but the 36v - 400 watt bulb could be a par type bulb, which would have the built-in reflector. Sorry I'm not much help. If you have time read the thread "DIY video Projector", there is a ton of info. Yes, it will take about a week because of so many posts but you can learn so much about DIY projectors.

http://www.diyaudio.com/forums/showthread.php?s=&threadid=281

Good luck 🙂

Zaner21
 
#10
Thank You All (especially zaner, dave and cookie)! My DIY-Projector is almost ready! 😀 Only cooling left.

How can i improve the picture? More Lumens? (Dont know how many my ohp got, maybe about 1k, i think) i use my wall as a screen, should i buy a better screen?

Are the results good or bad?

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I guess i will play a little with this self-made projector and buy a real one next year, i really like it that way and tomorrow i try my xbox 360... 😀
 
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